what does array length return code example

Example 1: array length javascript

var numbers = [1, 2, 3, 4, 5];
var length = numbers.length;
for (var i = 0; i < length; i++) {
  numbers[i] *= 2;
}
// numbers is now [2, 4, 6, 8, 10]

Example 2: js array of length

//initializes an empty array of length 4
new Array(4);